19309920 has 144 divisors (see below), whose sum is σ = 70843248. Its totient is φ = 4408320.

The previous prime is 19309919. The next prime is 19309921. The reversal of 19309920 is 2990391.

It is an interprime number because it is at equal distance from previous prime (19309919) and next prime (19309921).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19309921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23110 + ... + 23930.

It is an arithmetic number, because the mean of its divisors is an integer number (491967).

Almost surely, 2^19309920 is an apocalyptic number.

19309920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19309920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35421624).

19309920 is an abundant number, since it is smaller than the sum of its proper divisors (51533328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19309920 is a wasteful number, since it uses less digits than its factorization.

19309920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 853 (or 838 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 19309920 is about 4394.3054058634. The cubic root of 19309920 is about 268.2832084486.

The spelling of 19309920 in words is "nineteen million, three hundred nine thousand, nine hundred twenty".